1. Field of the Invention
The present invention relates to a display apparatus, a display control apparatus, and a display control method as well as a program, and more particularly, to a display apparatus, a display control apparatus, and a display control method as well as a program configured to suppress the occurrence of burn-in.
2. Description of Related Art
Recently, an organic EL (Electro Luminescence) display using organic EL elements receives increasing interest as a type of FPD (Flat Panel Display), and the organic EL display has been under active development.
The current mainstream of FPDs is an LCD (Liquid Crystal Display). The LCD, however, is not a device that uses self-luminescent elements and has to use illumination members, such as a backlight and a polarization plate. The LCD therefore has problems, such as an increase of the device in thickness and insufficient luminance. By contrast, the organic EL display is a device that uses self-luminescence elements. The organic EL luminescence display is therefore advantageous over the LCD in that it can be thinner because a backlight or the like is unnecessary in principle and it can achieve high luminance.
In particular, a so-called active matrix organic EL display provided with a TFT circuit that performs switching in each pixel is able to hold-light ON each pixel and power consumption can be suppressed due to this ability. In addition, because the active matrix organic EL display can be increased in screen size and achieve higher definition with relative ease, active developments have been made and it is expected to become the mainstream of the next-generation FPD.
Incidentally, the characteristic of the organic EL elements varies or deteriorates with the ambient temperature or self-heating. Also, when videos are displayed, the temperature environment of the organic EL elements varies from one video to another. Deterioration conditions of the organic EL elements therefore may differ among portions within the panel. For example, in a case where the organic EL display is used as the display portion of a TV set, when reception channel information (a number indicating the reception channel) is kept displayed on the screen corner, the organic EL elements in the portion where the reception channel information is kept displayed deteriorate faster, and a so-called burn-in phenomenon occurs.
The burn-in phenomenon will now be described, for example, with reference to FIG. 1.
FIG. 1 shows a screen 11A in a state where the reception channel information is displayed and a screen 11B in a state where burn-in occurs.
For example, as is shown in FIG. 1, “12” is displayed on the upper right corner of the screen 11A as the reception channel information. When the reception channel information is kept displayed at the same position for a long time, burn-in occurs because the organic EL elements in this portion deteriorate. As is shown in the screen 11B in a state where burn-in occurs, when a bright video is displayed, burn-in appearing as dark “12” occurs in the portion where the reception channel information has been displayed (within a region encircled by a broken line in FIG. 1).
As a technique of mitigating or preventing such a burn-in phenomenon, for example, JP-A-11-26055 discloses a technique of displaying a video to be kept displayed fixedly by inverting the video at predetermined periods, or a technique of displaying such a video by shifting the video at predetermined periods. In a case where the video is displayed while being inverted at predetermined periods, the technique is effective for a monochrome display. However, for a color display, the inverted video becomes a totally different video. It is therefore difficult to adopt this technique to a color display. In a case where a video is displayed by shifting the video at predetermined periods, the display position is displaced. It is therefore unsuitable to adopt this technique when a still image is displayed.
In addition, for example, JP-A-2002-351403 discloses a method of extending the life by providing dummy pixels outside the display region to detect terminal voltages of the organic EL elements in the dummy pixels when they emits light as a degree of deterioration of the dummy pixels, and correcting a video signal on the basis of the detection result. However, with a correction on the basis of the detection result of the terminal voltages of the dummy pixels, merely the entire display region is corrected from the detection result and the organic EL elements within the display region are not corrected locally. It is therefore difficult to prevent burn-in that occurs locally with this method.
Also, JP-A-2006-201784 discloses a method of correcting a temperature by feeding back an output from a build-in temperature sensor by providing the temperature sensor on the periphery of the panel. However, in a case where the temperature sensor on the periphery of the panel is used, it is possible to detect the overall temperature, but it is quite difficult to accurately detect the temperature distribution within a display region where heat is chiefly generated. It is therefore difficult to prevent burn-in that occurs locally.